Field of the Invention
The invention relates to a bearing configuration for the rotational mounting of a component provided for rotational movement, including a positionally fixed sleeve on which the component is rotatably mounted by way of one or more bearing elements or in plain-bearing fashion.
A bearing configuration of that type serves for the rotational mounting of a component, that is to say a moving axle can be realized through the use thereof. In the present case, the bearing configuration includes a positionally fixed sleeve which, in effect, forms the bearing axis or axis of rotation. The component is rotatably mounted on the sleeve. That may be realized by way of one or more bearing elements, such as corresponding rolling bearings or the like, although it is alternatively also possible for the component to be mounted in plain-bearing fashion on a correspondingly low-friction sleeve.
Moving axles of that type are braked manually or electrically, depending on the usage situation, in order to hold the previously moved component in a desired position. The braking torque of the axles is dependent on the inertia and on the possibility, defined by the structural space, of providing a suitable braking device. The use of standardized brakes is made difficult, in particular, due to the inertia and the often small amount of available structural space.
Summary of the Invention
It is accordingly an object of the invention to provide a bearing configuration for the rotational mounting of a component provided for rotational movement and a medical examination device including the bearing configuration, which overcome the hereinafore-mentioned disadvantages of the heretofore-known configurations and devices of this general type and in which the bearing configuration, due to a small construction, can be integrated into a correspondingly small structural space, but nevertheless provides high braking torques.
With the foregoing and other objects in view there is provided, in accordance with the invention, a bearing configuration for the rotational mounting of a component provided for rotational movement, comprising a positionally fixed sleeve on which the component is rotatably mounted by way of one or more bearing elements or in plain-bearing fashion. A pressure element is provided in the interior of the sleeve, by way of which the sleeve can be radially expanded and placed in frictional contact with the component which is spaced apart by way of an air gap.
In the case of the bearing configuration according to the invention, the positionally fixed sleeve not only serves for defining the bearing axis or axis of rotation itself, that is to say it not only bears the component to be mounted. Rather, the positionally fixed sleeve also serves as the braking element itself, by way of which the rotatably mounted component can be braked. For this purpose, according to the invention, a pressure element is provided in the interior of the sleeve. Through the use of the pressure element, a pressure can be exerted on the sleeve at the inner side of the sleeve, in such a way that the sleeve is expanded radially, albeit slightly. In this way, an air gap that exists between the outer side of the sleeve and the component, or the inner side of the bearing eyelet on the component, is bridged. In other words, with sufficient internal pressure and expansion of the sleeve, the outer side of the sleeve comes into frictional contact with the component or with the inner side of the bearing eyelet. Consequently, frictional engagement, and braking of the component, are realized.
Since the frictional engagement is realized only between the sleeve and the component, and the pressure element itself serves merely for imparting the required internal pressure, it is consequently the case that the pressure element is not at any time subjected to the braking or friction torque itself, so that the pressure element is not in any way impeded by the braking process itself.
Since the pressure element is integrated into the sleeve that forms the bearing axle, it is consequently the case that an extremely compact construction of the bearing configuration is realized, in such a way that a bearing configuration of this type can be integrated even in a very small structural space. At the same time, a very high braking torque can be transmitted, which, depending on the construction of the bearing configuration, may amount to several tens of Nm to several hundred Nm.
The air gap itself should be as narrow as possible, and should have a width of between 5 μm and 500 μm, in particular between 10 μm and 200 μm. The size of the air gap is ultimately dependent on the deformability of the sleeve and on the pressure that can be generated by way of the pressure element.
The pressure element itself may be a hydraulically or pneumatically or mechanically operating element. A hydraulically or pneumatically operating element has, for example, a cylinder section and a piston, in which the piston is moved in the hydraulic-fluid-filled or gas-filled cylinder for the purposes of pressure generation. In this case, the cylinder wall expands and presses against the interior of the sleeve, which leads to the expansion of the sleeve. Alternatively, it is also possible for a mechanism to be provided which is externally actuated and by way of which the pressure element is radially expanded for the purposes of pressure generation. For example, a movable cone is conceivable which is pressed into a recess of compatible shape defined by way of multiple radially movable segments, in such a way that the segments are displaced radially. Disk springs or spring packs which, under load, expand radially and act on the shell of the pressure element are also conceivable.
In the same way as the basic mode of operation of the pressure element itself may differ, different measures for actuating the pressure element are also conceivable. The pressure element is externally actuated. In a first alternative of the invention, the pressure element may be hydraulically or pneumatically actuated. That is to say, a corresponding hydraulic or pneumatic system is provided which can be correspondingly actuated or controlled by the user and which in turn actuates the pressure element in accordance with the construction thereof.
In this context, it is for example possible for a pressure-generating device to be provided, by way of which a pressure can be hydraulically or pneumatically exerted on the pressure element for the actuation thereof. The pressure-generating device, a suitable pump, is for example connected to an input of the pressure-generating element through a corresponding hydraulic or pneumatic line. If the pump is actuated by the operator, a corresponding pressure is generated, in such a way that the pressure-generating element is actuated and the braking process is initiated.
As an alternative to this, the pressure element may also be actuable by an electric motor. For this purpose, it is expediently the case that an electric motor is provided by way of which the pressure element is actuable directly or through an actuation mechanism. The electric motor may, for example, be coupled directly to the pressure element, in accordance with the construction thereof in terms of function. The electric motor may thus act directly on the piston, described by way of example in the introduction, of the pressure element or the like. Alternatively, the electric motor may also be positioned externally with respect to the pressure element and coupled thereto by way of a corresponding actuation mechanism, for example one or more suitable rods or levers, in such a way that a movement of the electric motor leads to a corresponding movement of the actuation mechanism and thus an actuation of the pressure element.
The actuation of the pressure-generating element or of the electric motor is preferably remote-controllable. This makes it possible for the operator to actuate or release the brake even from a distance. As an alternative to this, a direct manual actuation of the pressure-generating element, that is to say of the pump of the electric motor, is self-evidently also conceivable.
In a third alternative, the pressure element may finally be mechanically actuable. In this case, therefore, the pressure element, in accordance with the construction thereof in terms of function, is actuated by way of a pure actuation mechanism. For this purpose, a manual actuation element, in particular in the form of a lever, may be provided, which is actuated by the operator. The actuation element, that is to say for example the lever, may then act directly on the pressure element, that is to say it may be coupled directly thereto.
Alternatively, the actuation element, that is to say for example the lever, may also be coupled to the pressure element through an actuation mechanism in the form of one or more connecting rods or the like. If necessary, it is possible through an actuation mechanism of this type—and this also applies in the case of a coupling of the electric motor through an actuation mechanism—for a transmission ratio to be realized in order to yet further increase the actuation force.
The component itself which is mounted on the sleeve is preferably a toothed wheel or a toothed wheel segment. The toothed wheel or toothed wheel segment meshes, for example, with a further toothed wheel or toothed wheel segment which is to be arrested and which is in turn connected to the component which is to be braked by way of the bearing configuration. The bearing configuration thus serves in this case both for the mounting of the toothed wheel as well as for a brake device for an external component which is to be braked, which component is connected by way of its own toothed wheel or toothed wheel segment to that of the bearing configuration. Such a component associated with the bearing configuration may for example be the C-arm, which is pivotable about a vertical axis and is part of a medical examination device.
Aside from the bearing configuration itself, the invention also relates to a medical examination device. Therefore, with the objects of the invention in view, there is also provided a medical examination device, comprising a C-arm together with a radiation source and a radiation receiver. The C-arm is rotatably mounted on a device frame and the C-arm is associated with a bearing configuration of the type described above. An example of the integration of a bearing configuration of this type is a medical examination device in the form of a C-arm system. A C-arm system of this type includes a radiation source and a radiation receiver which are disposed on the C-arm. The C-arm is in turn movable about multiple axes relative to a device frame. Normally, a C-arm of this type can be pivoted orbitally (along the C-arc), angularly (about a horizontal axis) and about a vertical axis (swivel axis), wherein the three axes are orthogonal to one another. One axis with which a bearing configuration of this type can be associated is, for example, the vertical axis, that is to say the swivel axis.
Through the use of this bearing configuration, the C-arm can be braked and arrested as required. For this purpose, the bearing configuration component which can be braked is mechanically coupled to the C-arm, in such a way that the braking of the component inevitably also brakes the C-arm movement.
The bearing axis of the bearing configuration is expediently parallel to the axis of rotation of the C-arm, wherein the two axes are preferably vertical axes.
The C-arm expediently has a toothed wheel or a toothed wheel segment, the bearing configuration also has, as a component, a corresponding toothed wheel or toothed wheel segment, and the toothed wheels or toothed wheel segments mesh with one another. If the toothed wheel on the bearing configuration is braked and arrested by way of the integrated brake device, the C-arm is inevitably also braked.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a bearing configuration for the rotational mounting of a component provided for rotational movement and a medical examination device including the bearing configuration, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.